1. Field of the Invention
The invention relates to a ceramic lining for walls of combustion spaces subjected to high temperatures, in particular combustion chambers for gas turbines, the lining comprising individual elements which are fastened on the metallic wall by means of holding devices.
2. Discussion of Background
The use of ceramic materials for the lining of combustion spaces subjected to high temperatures is known.
Lining with refractory elements based on oxidic materials may be regarded as prior art. Apart from the low mechanical stability and the thick-walled, heavy construction, these linings have the disadvantage that the individual elements cannot be removed non-destructively. In addition, the oxidic materials used for these linings are not capable in terms of material properties of withstanding the ever increasing mechanical and thermal loads, for example in gas turbine combustion chambers.
A structure which is similar in principle, comprising interlocking individual elements without a solid connection of the individual parts, such as is described for example in DE 2 854 580, is likewise unsuitable for use in heavy-duty industrial combustion chambers.
Releasable connections of ceramic individual elements are almost always based on the use of cooled metallic holding devices (for example U.S. Pat. No. 2,548,485), which at least partly counteract a major advantage of the concept--that of creating a quasi adiabatic combustion space.
In EP 080 444 B2 it is proposed for a cast refractory lining of a furnace to sinter the anchoring irons into a refractory composition. This then forms with the anchoring irons anchoring elements, which are fastened on the furnace wall by bolts. This has the disadvantage that the mechanical properties of the component are impaired by the inhomogeneities within the ceramic structural element.
For combustion spaces of small dimensions, there are known types of design for constructing the wall of the combustion space from annular elements which, apart from axial fixing, only have to be centered. However, for technical manufacturing and production-related reasons, this concept cannot be used for larger combustion spaces.
The currently available high temperature resistant structural ceramics, such as for example silicon carbide SiC and silicon nitride Si.sub.3 N.sub.4, are not suitable as a lining for use in industrial combustion chambers which comprises an interlocking structure of individual elements without a solid connection of the parts.